Aoyama Tessan was a man who has connections to the story of Banchō Sarayashiki, his role is slightly different depending on the version of the folktale.
In the Harima Province version, he is a Samurai who serves the lord of the Province. Aoyama wants to be ruler instead and so plots to poison him using his servant Okiku. The posioning is discovered, and eventually Okiku is killed. She then returns as a ghost, and the Lord learning of this ghost makes Aoyama commit ritual suicide.
In the Edo Version he is the Lord, and has a mansion in Edo. He cuts off the middle finger of Okiku for breaking a priceless plate (one of ten), and has her thrown in a dungeon. She escapes and throws herself down a well. Her ghost then haunts the well, meaning Aoyama is forced to bring a priest to exorcise her. It is also said that later in his life, his first child was born with her middle finger missing.1
1. Yoda, H & Alt, M. (2012) “Yurei Attack: The Japanese Ghost Survival Guide” Tokyo: Tuttle Publishing.
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